Cermet has excellent wear resistance so that it is used as a cutting tool. When a work piece material is subjected to cutting processing by using a cutting tool made of a cermet, it has been known to obtain a smooth finishing surface. As a conventional technique of the cermet, there has been known a cermet in which a hardness at the surface portion of the cermet is heightened to improve wear resistance (for example, see Patent Literature 1.). Also, there has been known a cermet in which structures at the inside and the surface portion of an alloy are controlled to improve characteristics (for example, see Patent Literature 2.).